Key-hole guard



` UNITED f STATES PATENT OFFICE.,

JOSIAH H. BROWNE, OF SALEM, MASSAOIIUSETTS.

KEY-HOLE GUARD.

SPECIFICATION forming part of Letters Patent No. 227,725, dated May 18, 1880.

l Application filed September 14. 1877.

To all whom t may concern:

Be it known that I, J osIAn EBROWNE, of Salem, in the county of Essex and State of Y Massachusetts, have invented a new and useful Improvement in Door-Locks5 and I do hereby declare that the followingisa full, clear7 and exact description of the same.

My invention is an improvement in the class of mortise and rim locks having keyhole guards consisting' of pivoted plates adapted to swing over the key-hole and prevent the insertion of picks on the outer side of the lock whenever a key is inserted on the inner side.

My improvement consists in the construction and arrangement of sliding guards and the devices which col-operate with them, so that the movement of one guard causes the opposite movement of the other, as hereinafter described.

In accompanying drawings, Figure l is side perspective view of a mortise-lock provided with my improved key-hole guard. Fig. 2 is a perspective view of a portion of such lock, part being broken away, showing the key inserted. Fig. Sis a perspective View of both key-hole guards, showing different sides of the same. Fig. 4 is a side view of the key for working the lock. Fig. 5 is a cross section on line x x, Fig. 1.

The key-hole slides A A are oblong rectan-v gular plates, each having a key-hole in one end and a T-shaped lug, D, on its inner side. The guard-plates A are applied to opposite sides of the lock-case (l, and arranged to slide between parallel horizontal ribs f, so as to cover or uncover the keyhole, according to their position.

The plates are prevented from being detached from the lock proper, C, by lugs D, whose shoulders overlap the inner edges of slots in which the lugsD slide.

Alever, B, is pivoted horizontally at the middle of its length in a slot in the rear edge of the lock-case C, at apoint contiguous to the key-hole. v N

The guards A A are held pressed back against lthe respective ends of the lever B by means of springs a, whose free ends bear against shoulders of lugs D, as shownin Figs. 2 and 5.

The key-holes in the guards A are so located that they partly coincide with-that is,

' partly cover-thel key-hole in the sides of the lock -proper when both guards are in their normal position, as shown in Figs. 2, 5; but when one guard A is pushed back or adjusted so as to bring its key-hole into perfect coincidence with the adjacent key-hole in the lock proper, (l, the lever B is thereby thrown into diagonal position and caused to press against the opposite guard A, so that it is slid .forward and made to cover its adjacent key-hole. This position and relation of parts are shown in Fig. 2, in which one guard is pushed back to expose one of the lock keyholes, and the other forward to uncover the key-hole upon the opposite side.

The mechanical means I employ to move the guards is the key c, having a point which is made conical, and thereby adapted to wedge itself into the partly-coincident key-holes of guards and lock proper and to force back the guards.

When fully inserted the point of the key enters a socket,l d, in the lug D of the opposite guard A, and thereby serves to hold or assists in holding said guard firmly in its position.

On removing the key c the springs a will cause the guards t0 resume their former or normal position. The key c therefore serves not only to operate the `guards A in the iirst instance, but to hold them in such position that the one on the opposite side of the lock will cover the adjacent key-hole, and thereby frustrate any attempt to pick the lock by inserting picks, Sto., through the key-hole.

What I claim isl. The combination, with a lock, substantially as described, of two movable slotted guards, one on each side, a lever, B, pivoted tothe lock-case, and springs which act on the guards, as shown and described, whereby one of the guards is slid forward to cover the adjacent key-hole when the other is pushed back to uncover its adjacent key-hole, as specied.

2. The combination ofthe key having conical or tapered point with the slotted movable and spring-actuated guards having lugs provided with sockets d, the pivoted lever B, and the lock-case, substantially as shown and described.

IOO

JOSIAH H. BROWNE.

Witnesses S. LEVY, JOHN O, CONNOR. 

